Surface-modified CdTe PEC solar cells

The effect of ruthenium surface modification is shown to improve considerably the properties of p-CdTe PEC solar cells. The dark I-V characteristic shows a decrease in J(0) from 2.8 x 10 to the -7th A/sq cm to 5.1 x 10 to the -8th A/sq cm and a decrease in ideality factor n from 2.72 to 1.54. Under AM 1 illumination, open circuit voltage increased from 0.63 to 0.92 V vs NHE, short-circuit density from 2.17 mA/sq cm to 3.23 mA/sq cm and fill factor FF from 0.38 to 0.48. The minority carrier diffusion length L(n) is shown to increase from 0.72 micron to 0.99 micron after ruthenium modification. The maximum current density obtainable is limited by material resistivity.